Blade sharpening device for rotatable chopping cylinders including hydraulic drive means

ABSTRACT

A blade sharpening device for a rotatable chopping cylinder for a forage harvester or the like, which cylinder has a plurality of circumferentially spaced and generally parallel blades that are of a generally spiral shape. The device includes a carriage that moves along parallel to the cylinder and has a sharpening tool extending from it for contact with the blades, guide means connected directly to the carriage for guiding abuttment with a succeeding blade whereby as the carriage moves along the axis of the cylinder, and a compact hydraulic motor for driving the grinding wheel. A hydraulic system for such a blade sharpening device.

Feb. 4, 1975 United States Patent [19] Fleming BLADE SHARPENING DEVICEFOR ROTATABLE CHOPPING CYLINDERS Primary Examiner-Al Lawrence SmithAssistant Examiner-Nicholas P. Godici Attorney, Agent, or FirmJames E.Nilles .s S W A m Me B E! VS R ow Cn Um Uh MF F W m GP N ea mew m Nm II[57] ABSTRACT A blade sharpening device for a rotatable chopping [73]Assignee: Gehl Company, West Bend, Wis.

Feb. 25, 1974 [22] Filed:

cylinder for a forage harvester or the like, which cylinder has aplurality of circumferentially spaced and generally parallel blades thatare of a generally spiral 21 Appl. No.: 445,677

52 us. 51/249,51/1345 F, 59610245407, Shaw The device includes acarriage that moves along parallel to the cylinder and has a sharpeningtool extending from it for contact with the blades, guide meansconnected directly to the carriage for 4 7 154 M 4 b ,4 HM 2 B 2 M 3 86M45 9 B5 MUZ NW7 n4 ""2 "0 m r "a e "S .1 0 d .l Mk IF 1] loo 55 ll.

guiding abuttment with a succeeding blade whereby as the carriage movesalong the axis of the cylinder, and

References Cited UNITED STATES PATENTS a compact hydraulic motor fordriving the grinding wheel. A hydraulic system for such a bladesharpening device.

2,166,940 7/1939 Conradson.......................... 2,839,874 6/1958Maker....... 3,724,139 4/1973 Leverenz PATENTED v 1.863.403

- sum 1 or 6 PATENTEDFEB I I 3863.403

SHEET 2 OF. 6

PATENTED FEB 4|975 FIG. 6

SHEET GDP 6 ii? I I 14o F M LL51! l Mel A30 OPEN SYSTEM CLOSED SYSTEM 1BLADE SHARPENING DEVICE FOR ROTATABLE CHOPPING CYLINDERS INCLUDINGHYDRAULIC DRIVE MEANS BACKGROUND OF THE INVENTION This inventionpertains to apparatus for sharpening the blades of a cylindrical rotorof a forage harvester, or the like, and without the necessity ofremoving the knives from the harvester. It is an improvement over thesharpener shown in US. Pat. No. 3,724,139, issued Apr. 3, 1973 andassigned to an assignee common with the present invention.

SUMMARY OF THE INVENTION The present invention provides a bladesharpening device for a rotatable chopping cylinder of the type having aseries of circumferentially spaced, generally parallel and spiral shapedblades. The device includes a carriage that moves parallel to the axisof the cylinder and has a grinding wheel for engagement with one of theblades as it moves longitudinally of the cylinder, and a guiding elementthat contacts the succeeding blade and thereby guides the wheel in anexact manner over the blade to be sharpened.

The invention also includes a compact hydraulic motor which permitscomplete adjustment of the grinding wheel relative to the blade so thatminimal relief grinding of the blade is assured. The invention alsoincludes a hydraulic circuit for driving the hydraulic motor, thecircuitry being such that the sharpening apparatus and circuitry can beused with various tractor systems including open center or closed centersystems, fluid pressure sources of varying output capacity, tractiveunits having different engine speeds and other variables.

The arrangement is such that an excess flow check valve located in thepressure line from the source of fluid pressure will automatically shutoff the motor when excessive flow passes through the check valve, and inthis manner, the motor is prevented from overspeeding and thereby itsattached grinding wheel will not break apart due to centrifugal forcesbut on the other hand, the wheel will not be under speed to therebygrind inefficiently. The circuitry is such that the operator can easilydetermine the maximum speed of the grinding wheel which can be attainedwithout popping the excess flow valve. Another aspect of the inventionrelates to an adjustable needle valve which controls the delivery of theclosed center system pump by varying the downstream pressure of thepump.

These and other objects and advantages of the pres ent invention willappear hereinafter as this disclosure progresses, reference being had tothe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of aportion of aforage harvester embodying the present invention I showingcertain parts being swung away from their normal operating position andother parts being shown as broken away or removed for the sake ofclarity in the drawings;

FIG. 2 is an end elevational view of the device shown in FIG. 1, but onan enlarged scale and showing certain parts being broken away or removedfor the sake of clarity, and showing the grinder carriage in theposition when it commences its sharpening travel at one end of theknife;

FIG. 2a is a sectional view taken generally along the line 2a-2a in FIG.2, certain parts being shown as broken away or removed for the sake ofclarity;

FIG. 3 is a view taken generally along the line 33 in FIG. 4, certainparts being shown as broken away for the sake of clarity, and showingthe carriage at one extreme end of its travel, before contact with aknife to be sharpened;

FIG. 4 is a sectional, plan view taken generally along the line 44 inFIG. '2, but showing the carriage when about half-way through asharpening pass over the knife, certain parts being shown as broken awayor removed for the sake of clarity;

FIG. 5 is an enlarged, exploded view of the fluid motor and grindingwheel and its mounting and adjustment to the carriage;

FIG.'6 is a circuit of an open center system hydraulic circuit usablewith the present invention; and

FIG. 7 is a circuit diagram of a closed center system usable with thepresent invention.

DESCRIPTION OF A PREFERRED EMBODIMENT The general organization of theinvention as applied to a forage harvester is shown in FIG. 1, theforage harvester including a housing H supported on ground engagingmeans such as the wheel means W, a blower B attachable to the housingfor receiving the cut crop from the housing via the blower opening 1.The blower includes a fan F rotatable mounted therein which delivers thecut crop to the tangentially extending chute C in the known manner. Theblower B has been shown for purposes of clarity as being swung to therear of the housing, but it will be understood that in operation, theblower B will be swung snugly against the housing so that the opening 1is in immediate adjacency with the housing for receiving cut cropstherefrom. Furthermore, when the machine is operating in the field,another cover (not shown) would enclose the top of the chopping cylinder5, to be described.

A conventional chopping cylinder 5 is rotatably mounted in the housingand rotation in the direction indicated by the curvilinear arrow in FIG.2. The cylinder has a series, for example six shown, of blades ll, l2,l3, l4, l5 and 16 which are circumferentially spaced and generallyparallel to one another, and are mounted on the cylinder rotor frame 18.These Conventional blades are arranged to define the periphery of thecylinder and are generally spiral in form. The blades include a frontsharpening edge defined by the respective bevelled portions, for exampleIla of the blade 11 which is shown in the position for being sharpened.These edges must be reground periodically to insure sharpness of theblade. The cylinder 5 also includes a plate-like member 20 rigidly fixedto the outer end of the cylinder shaft 21 and located on the outside ofthe housing H. This plate-like member has a series of projections 22arranged around its periphery, one for each of the blades. As shown inFIGS. 1 and 2, spring loaded means 25 are provided to act between thehousing H and the plate-like member so as to bias the cylinder in thedirection of rotation indicated by the curvilinear arrow in FIG. 2. Morespecifically, the spring loaded means 25 includes an extensible strut 26which is pivoted at 27 to the housing and which has a clevice 28 fixedby a bolt means 29 to the other end of the extensible strut 26. A spring30 acts between an anchor 31 on the strut and the extensible end 32 ofthe strut to thereby urge the bolt means into firm contact with theprojections 22 and consequently bias the cylinder in the direction ofrotation noted, for a purpose that will hereinafter appear.

Guide track means in the form of parallel rods 40 and 41 are mounted onthe housing and are arranged in parallelism with the cylinder axis andadjacent the top opening 42 in the housing. One of said rods is mountedon each side of the housing and extend generally coextensively in lengththerewith.

A travelling carriage 50 is slideably mounted on each of the guide rods40 and 41 so that the carriage can be slid from one end of cylinder tothe other, more specifically across the full length of the cylinder 5. Asharpening tool in the form of a rotatable grinding wheel 52 extendsfrom a hydraulic motor 53 so that the latter can drive the wheel 52through its drive shaft 54.

The grinding wheel 52 and the associated hydraulic motor 53 areadjustable as a unit relative to that blade of the cylinder to besharpened, as follows. The hydraulic motor in turn is rigidly carried onthe carriage by a motor mounting plate 55 which has a generallyvertically extending torque arm 56 rigidly fixed thereto (FIG. 5). Thetorque arm is slideably mounted in aperture 57 formed in a motor support58.

The motor support 58 is pivotally mounted on the carriage 50 by means oftwo stub shafts 59 and 60 which extend through aligned holes 58a and 50aof the support 58 and carriage 50, respectively.

A threaded member 61 is rotatably mounted at one end in mounting plate55 and is then in threadable engagement at 62 with the support 58. Ahand adjusting knob K is fixed at the end of threaded member 61.

A link 65 is connected by pin 63 to the support 58 and by aneccentrically movable bolt 64 to the carriage 50.

The above construction permits the arm 58, motor 53 and wheel 52 to beadjustable in a generally vertical direction relative to the blade to besharpened, and this is accomplished by rotating the knob K in onedirection or the other. Adjustment of the eccentric bolt 64 varies theangle of the motor 53 and its grinding wheel 52 relative t0 the blade toinsure that the proper angle is ground for the bevel edge 11a.

Guide means 70 are provided for insuring that the cylinder rotates theproper amount as the carriage moves axially thereover, so that thegrinding wheel is at all times properly positioned in respect to theblade 11 being sharpened and that the proper edge is formed on theblade. This guide means includes an arm 71 which is rigidly fastened bybolts 73 (FIG. 4) to the carriage proper, which arm extends rearwardlyfrom the grinding wheel 52. The guide means includes a pair of rollers76 at its lower end. The rollers are adapted to roll along the innerside 77 (FIGS. 2 and 4) of the blade 16 which succeeds or follows theblade 11 being sharpened. The guide means also includes a shoe 78 havinga curved or angled leading edge 79 so that when the carriage is at oneextreme end of the cylinder and the guide means is about to make contactwith the corresponding end of blade 16, the guide means will make propercontact with the blade 16 to properly orientate the guide means andcarriage in respect to the cylinder prior to the sharpening pass of thewheel 52 over the blade.

As previously mentioned, the spring loaded means 25 is provided forbiasing the cylinder in the direction of rotation indicated in FIG. 2 bythe curvilinear arrow, and the blade 16 is held snugly against therollers 76 of the guide means as the sharpening tool 52 moves axiallyalong the cylinder. Thus, as the sharpening wheel 52 moves along thelength of the cylinder to sharpen the blade 11, the cylinder must alsorotate sufficiently, because of the spiral nature of the blade shape, toinsure that the wheel 52 is presented at the proper attitude to theblade along its entire length.

Manually operated drive means are provided for driving the carriage 50along the length of the guide track means 40, 41 in either direction.This drive means includes a crank which can be continuously rotated bythe operator so as to reciprocate the carriage along the guide trackmeans. More specifically, the crank has a relatively small sprocket 92fixed thereto and over which the endless chain 93 is trained. A shaft 94is fixed within the housing and has a pair of sprockets 95 while anotherendless flexible member in the form of a roller chain 97 is trainedaround sprocket 96. Another shaft 98 is also mounted in the housing andhas a sprocket 99 mounted thereon and over which the chain 97 is alsotrained.

A drive chain pin 100 (FIGS. 3 and 4) is carried by the chain 97 andextends from the side thereof, a plate member 101 is fixed to thecarriage and has a vertical slot 102 formed therein for the reception ofthe chain pin 100. Thus the pin 100 travels in an orbital path with thechain 97 when the operator turns the crank 90. The pin 100 consequentlycarries the carriage with it via the connecting slotted plate 101. Ateither end of travel of the carriage, the pin moves vertically in theslot 102 and continued rotation of the crank 90 then causes the pin toreverse its travel, carrying with it the carriage. As a result,continuous rotational motion of the crank 90 by the operator in onedirection is translated into reciprocating motion of the carriage. Thusthe grinding wheel 52 can be caused to make various passes, in eitherdirection, over the blade being sharpened.

HYDRAULIC CIRCUIT The hydraulic circuit used in the present inventionare shown by way of example in FIGS. 6 and 7. Generally, fluid pressureconduits 130 and 13] extend from the hydraulic motor 53 and to a sourceof pressure fluid, such as a fluid pump 114 carried on the harvester ora propelling vehicle (not shown).

The fluid motor 53 has two check valves 116 and 117 therein. Valve 116allows the motor to coast to a stop when the pressure is suddenly shutoff by a control valve 120 and check valve 117 prevents the motor 53from being driven backward due either to improper connection of thehydraulic conduits and 131 or operating the tractor control valve in thewrong direction.

Referring more specifically to FIG. 6, this illustrates an open centerhydraulic system and has a fixed displacement pump 114 whose outputvaries depending on the speed of the engine of the propelling vehicle(not shown) for the harvester and also depending on the size of the pumpof any particular propelling vehicle. The four-way control valve 120 isof the conventional type and is controlled by the operator from the cabof the propelling vehicle, such as a tractor and this four-way controlvalve has three positions as schematically indicated. Moving the valveto the left as viewed in FIG. 6 delivers pressurized fluid to the righthand line 130 and of course moving the valve spool to the rightpressurizes the left hand line 131. With the invention as abovedescribed, the valve 120 is shifted only to the right so thatpressurized fluid enters the left conduit 131.

The closed center system shown in FIG. 7 uses a variable displacementpump ll4a whose delivery is independent of the tractor engine speed, butthis pump varies its output by sensing the downstream pressure. In thismanner, the four way valve 120 is shown in the closed position whereinno fluid is being delivered to the system and the pump is de-stroked.Positioning the control valve 120 to the left or to the right producesthe same effect as in the open center system of FIG. 6, while the pumpstrokes itself to produce flow of pressurized fluid.

With either the above open or closed systems, no two tractors ordifferent models or manufacture will in all probability deliver the sameoutput per minute while running at rated engine speed. Furthermore therevolutions perminute of the fluid motor 53 of the grinding wheel isdirectly proportional to the gallon per minute of fluid pressuredelivered to it. Therefore, in accordance with the present invention,excess flow check valve 140 is provided in the line and adjustableneedle valve 142 in the same line is also provided, that is between theflow control valve 120 and the fluid motor 53.

The grinding wheels such as are used with the present invention must notrun excessively fast or they will break and disintegrate due tocentrifugal force. On the other hand these wheels must not beunder-speeded or they will not grind efflciently. To assure that thevarious tractors usable with the present invention will deliver theproper amount of fluid to the motor 53, the excess flow check valve 140is placed in the pressure line l3l and this valve automaticallyfunctions to shut off the line when the flow of fluid in the line is inexcess of a predetermined amount, thereby stopping the fluidmotor 53 andpreventing its overspeeding.

With open center type hydraulic tractors, the operator starts thehydraulic pump 53 at low engine speeds and gradually increases thatspeed, thereby increasing delivery of the pressure fluid andconsequently increasing motor speed until the excess flow check valve140 closes. The operator can then note the tachometer setting of thetractor engine set to a particular point. Then the operator can restartthe engine again at low speed and bring the tachometer which readsengine speed up to a point just below relief setting of the valve 140which he has just noted. The operator is then ready to perform thegrinding function at the proper hydraulic motor speed. ln this case, hedoes not use the adjustable needle valve 142 and instead it is left inthe wide open position.

With most closed center system tractors, the operator sets the tractorengine speed and having set the adjustable needle valve 142 to the fullyshut position before starting, he then gradually opens the needle valve142 until the excess flow check valve 140 closes. The operator thencloses the adjustable needle valve 142 slightly, then restarts theengine and is then operating the motor at just the correct speed. Theadjustable needle valve 142 is thus a device which controls the deliveryof a closed center system pump by varying the downstream pressure of thepump.

Once the needle valve 142 is set as above indicated and the tachometerreading is noted, the adjustments 5 described above are no longernecessary when using the same tractor for operating the hydraulic motor53.

The present circuitry is capable of accommodating all existing tractorsystems regardless of their output capacity, and results in a simplesystem for controlling the speed of the hydraulic motor 53 with bothopen or closed center supply systems.

I claim:

1. A blade sharpening device for use with a forage harvester having ahousing and a cutting rotatably retained within the housing and having aplurality of circumferentially spaced spiral shaped cutting blades, thesharpening device comprising: guide track means supported on saidhousing, a carriage movably supported on said track means for movementgenerally parallel to the cylinder axis, a grinding wheel on thecarriage and engagable with one of said cylinder blades, a hydraulicmotor connected to and for driving said grinding wheel, and a hydrauliccircuit for supplying controlled pressure fluid to and from said motor,said circuit including a fluid pressure pump, a control valve forreceiving pressure fluid from said pump and delivering it to said motor,and an excess flow check valve and also and adjustable needle valve bothlocated between said control valve and said hydraulic motor.

2. The device set forth in claim 1 including a motor assembly whichincludes said grinding wheel and said hydraulic motor, a motor supportpivotally mounted on said carriage, said assembly having means for beingshiftably mounted on said support, an adjustable connection between saidsupport and said assembly for varying the grinding wheel relative to ablade being sharpened.

3. The device set forth in claim 2 including eccentric adjusting meansbetween said carriage and said support to vary the angle of saidgrinding wheel relative to said blade being sharpened.

4. A blade sharpening device for use with a forage harvester having ahousing and a cutting cylinder rotatably retained within the housing,the cylinder being composed of a plurality of circumferentially spacedand substantially parallel, peripheral and spiral shaped cutting bladessupported on a frame, the sharpening device comprising; guide trackmeans supported on said housing and dispositioned parallel to thecylinder axis, a movable carriage supported on said track means formovement parallel to the cylinder axis, a motor support pivotallymounted on said carriage, a motor assembly including a fluid motor and agrinding wheel drivingly connected therewith, said assembly having meansfor being shiftably mounted on said support and also having anadjustable connection with said support for varying the grinding wheelrelative to a blade being sharpened, an eccentric adjusting meansbetween said carriage and said support to vary the angle of saidgrinding wheel relative to said blade being sharpened and a hydrauliccircuit for supply controlled pressure fluid to and from said motor,said circuit including a fluid pressure pump, a control valve forreceiving pressure fluid from said pump and delivering it to saidmotor,-an excess flow check valve and an adjustable needle valve locatedbetween said control valve and said hydraulic motor.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 863,403 Dat d February 4, 19 7 5 Inventor (5) Philip F. Fleming It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

COLUMN 6, line 14, after "cutting", insert ---cyIinder--- Bigncd andSalad this Thirtieth Day of November 1976 [SEAL] Arrest:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner of Parentsand Trademarks

1. A blade sharpening device for use with a forage harvester having ahousing and a cutting rotatably retained within the housing and having aplurality of circumferentially spaced spiral shaped cutting blades, thesharpening device comprising: guide track means supported on saidhousing, a carriage movably supported on said track means for movementgenerally parallel to the cylinder axis, a grinding wheel on thecarriage and engagable with one of said cylinder blades, a hydraulicmotor connected to and for driving said grinding wheel, and a hydrauliccircuit for supplying controlled pressure fluid to and from said motor,said circuit including a fluid pressure pump, a control valve forreceiving pressure fluid from said pump and delivering it to said motor,and an excess flow check valve and also and adjustable needle valve bothlocated between said control valve and said hydraulic motor.
 2. Thedevice set forth in claim 1 including a motor assembly which includessaid grinding wheel and said hydraulic motor, a motor support pivotallymounted on said carriage, said assembly having means for being shiftablymounted on said support, an adjustable connection between said supportand said assembly for varying the grinding wheel relative to a bladebeing sharpened.
 3. The device set forth in claim 2 including eccentricadjusting means between said carriage and said support to vary the angleof said grinding wheel relative to said blade being sharpened.
 4. Ablade sharpening devIce for use with a forage harvester having a housingand a cutting cylinder rotatably retained within the housing, thecylinder being composed of a plurality of circumferentially spaced andsubstantially parallel, peripheral and spiral shaped cutting bladessupported on a frame, the sharpening device comprising; guide trackmeans supported on said housing and dispositioned parallel to thecylinder axis, a movable carriage supported on said track means formovement parallel to the cylinder axis, a motor support pivotallymounted on said carriage, a motor assembly including a fluid motor and agrinding wheel drivingly connected therewith, said assembly having meansfor being shiftably mounted on said support and also having anadjustable connection with said support for varying the grinding wheelrelative to a blade being sharpened, an eccentic adjusting means betweensaid carriage and said support to vary the angle of said grinding wheelrelative to said blade being sharpened and a hydraulic circuit forsupply controlled pressure fluid to and from said motor, said circuitincluding a fluid pressure pump, a control valve for receiving pressurefluid from said pump and delivering it to said motor, an excess flowcheck valve and an adjustable needle valve located between said controlvalve and said hydraulic motor.